Many drugs for use with medicament delivery devices are contained in so called cartridges that are generally shaped as glass tubes in which a stopper is positioned. The proximal end of the cartridge is arranged with a septum or a similar resilient membrane through which a distal end of a medicament delivery member can be pushed.
The devices are thus arranged with compartments in which these medicament containers may be placed and are further arranged with neck portions provided with attachment members intended to cooperate with corresponding attachment members on the medicament delivery members.
For a number of devices the medicament delivery members constitute injection needles. The injection needles could either be arranged to an attachment member that is designed to cooperate with corresponding attachment means on medicament cartridges in order to deliver a dose of medicament at the injection site of a patient. The injection needle could also be a part of a syringe, i.e. integrated with the medicament container.
Due to the risk of being unintentionally injured by the injection needle, but also for covering the needle before use for patients that are uncomfortable with seeing the needle during e.g. penetration, different covers, caps and/or shields and guards have been devised. These are often accompanied by spring members urging them in different directions in relation to the devices as well as locking members, releasable or non-releasable, for holding and locking the covers or shields in different positions.
Regarding the use of springs acting on the shields, they are often used to urge the shields in the proximal direction in a non-locked condition prior to drug delivery. One such device is disclosed in the document WO 2006/057604 having a needle shield that is released from a retracted position by a turning action of a dose setting member at a distal end of the device. The device of WO 2006/057604 comprises a number of functions such as mixing, priming, auto-penetration and auto-injection, making it complex with a plurality of components. Further, in order to release the needle shield, components need to extend through the whole device from the dose setting member. For some applications and uses, the device need not be so complex nor contain so many functions, but could yet be intuitive and easy to use.